As Joan said, this is a permissions problem. PHP doesn't have access to write to the file which keeps the Guestbook entries. In your FTP program, try right-clicking on the file "gb.entrys" (which, by the way, is a crass spelling error) and choosing "Properties" or "Permissions". There you may grant write access on the file. However, do not do this blindly! Instead, I recommend that you go to Google and try to learn a few things about file permissions.